Miller was relieved of his duties at the club this year, meaning the Gothenburg Great observed Milne's emotional outburst at Hampden this week as an interested neutral rather than Milne's fellow Aberdeen FC board member.
The Aberdeen chairman usually remains in the background but former Director of Football Miller believes his fury in front of the television cameras after the rejection of SPL reform showed exactly what Scottish football and his club means to him.
Milne's anger came as no shock to Miller, who is convinced the AFC chairman has the best interests of Aberdeen and Scottish football at heart.
Miller told the Daily Record: “It might not be a side of Stewart that people have seen often in public, but it’s certainly something I have witnessed a few times working with him for 10 years.
“His public persona might be different but don’t be mistaken. Stewart is a very determined guy and he has got a lot of grit and determination.
“There’s no doubting the passion for his club or for Scottish football. People might have the impression he would rather be away from the club [...] but I have never had the sense that was what he wanted to do.
“You could see the frustration because of all the work that was put in [to the league reconstruction plan] and how far they were down the road. Stewart has seen the constraints placed on the Scottish game and he has genuine concerns for where we are going.
“He is thinking about Aberdeen - but he has always looked at the bigger picture and the greater good of the game in this country. He will feel a lot of positive work has been undone now.”